harrog8 Posted July 12, 2004 Share Posted July 12, 2004 I've just had a new ECU fitted and mapped on the rolling road, I get lots of popping from the exhaust on overrun which sounds great, but what if any are the downsides. Link to comment Share on other sites More sharing options...
Tony C Posted July 12, 2004 Share Posted July 12, 2004 Blow the stuffing out yer silencer Link to comment Share on other sites More sharing options...
John Howe Posted July 13, 2004 Share Posted July 13, 2004 If your ECU is programmable, then you should be able to adjust it to kill the spark on the overrun - which will stop the banging. JH Deliveries by Saffron, the yellow 222bhp Sausage delivery machine Link to comment Share on other sites More sharing options...
Peter Carmichael Posted July 13, 2004 Share Posted July 13, 2004 Worth pointing out that a "rolling road session" might leave significant portions of the map "unmapped". There is so much attention to detail in progression from idle and high speed, WOT running that the part throttle and overrun positions can be completely overlooked. Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted July 13, 2004 Leadership Team Share Posted July 13, 2004 According to Dave Walker's book, popping on the over-run is often caused by a weak mixture at the high rev / low load sites. Increase the fuelling at zero load site across the rev range from around 2500 rpm upwards. Should do the trick , it certainly sorted mine. Stu. Link to comment Share on other sites More sharing options...
Sam Monoogian Posted July 13, 2004 Share Posted July 13, 2004 Going slightly off-topic but along the lines of what Peter was on about, one of my team-mates from Formula Student last year proudly proclaimed he'd mapped the engine on the dyno. When it came to testing the car would not respond well at all to any significant prods of the loud pedal, being hesitant and then spitting and banging before clearing its throat and going like sh*t off a shovel. The engine had only been mapped for steady state conditions and wasn't very good at transient responses. He's now employed at Cosworth 😬 Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted July 14, 2004 Leadership Team Share Posted July 14, 2004 Harrog8 - and the result is 🤔 Link to comment Share on other sites More sharing options...
Area Representative Paul Richards Posted July 15, 2004 Area Representative Share Posted July 15, 2004 Don't overlook the fact that popping exhaust can be caused by a defect gasket(s) on exhaust manifold. May not be related to ECU fitting. Paul Richards Joint AO - L.A.D.S. (Lancashire and District Sevens) Growing old is compulsory - Growing up is optional Link to comment Share on other sites More sharing options...
dave1968 Posted July 15, 2004 Share Posted July 15, 2004 does it do it on a completely closed throttle ? my car is 'silent' on a closed throttle but pops like buggery if on a trailing one...... Edited by - Dave68 on 15 Jul 2004 17:10:58 Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted July 15, 2004 Leadership Team Share Posted July 15, 2004 At a completely closed throttle, chances are the fuel cut-out has come into play (depending upon the ecu). If popping is experienced at slight throttle openings on the over-run, ie. low load sites, then usually the fuelling needs increasing a little at those sites. Stu. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now